bryce@COGSCI.BERKELEY.EDU.UUCP (05/20/87)
> [the 3-D glasses] > Why is the ST so well suited for use of this device? Could an 8-bit interface > for the 3D glasses be constructed?. I want concrete technical facts on why or > why not this would work. The glasses have two lcd shutters. The shutter has the ability to block one side of the glasses (via polarizaion) the other side may remain clear. So what you do is prepare two frames. One meant for the left eye and the other for the right. On veritcal blanking you switch eyes on the glasses and switch images on the screen. This is why they always have these demos in darkened rooms or with some sort of light sheild or dimmer. The darker it is, the less you notice the 30hz flicker. In a bright room with bright colors the image flickers a lot. In a very dim room with drab colors the image is solid. Happy mediums exist in between. There is nothing special about the ST that is suited for use of the device, with a simple interface an Atari 8-bit or Commodore-64, VIC-20, Coleco Adam, TI99/4A, PCjr, Spectrum, Sinclair QL, Amstrad or whatever could drive it. All a computer needs is some output bits, the ability to check for veritcal blanking and do a page-flip operation on the screen. High resolution graphics helps, but is not strictly necessary. ------------- Ack! (NAK,EOT,SOH) |\ /| . {o O} . bryce@cogsci.berkeley.EDU seismo!ucbvax!cogsci!bryce ( " ) U
john@viper.Lynx.MN.ORG (John Stanley) (05/21/87)
In article <8705200144.AA29716@cogsci.berkeley.edu> bryce@COGSCI.BERKELEY.EDU (Bryce Nesbitt) writes: > >So what you do is prepare two frames. One meant for the left eye and the other >for the right. On veritcal blanking you switch eyes on the glasses and >switch images on the screen. > >This is why they always have these demos in darkened rooms or with some sort >of light sheild or dimmer. The darker it is, the less you notice the 30hz >flicker. In a bright room with bright colors the image flickers a lot. >In a very dim room with drab colors the image is solid. Happy mediums >exist in between. The lcd shutters switch on and off at, as you mentioned, 30hz. The average human eye doesn't detect "flicker" until you get below 25hz. The problem is not "image flicker" but ambiant room lighting flicker. The problem with lights has to do with the flicker rate of the lights themselves heterodyning with the flicker of the glasses. This is especialy noticable if you are using the monochrome monitor (which produces much sharper 3d effects) since it refreshes at 70 hz producing a both-eye rate of 35hz. The lcd switching at 35hz and the lights switching at 30hz produces a noticable 5hz flicker which is the result of using the lcd glasses and could'nt be improved using any other <$1500 monitors... > >There is nothing special about the ST that is suited for use of the device, >with a simple interface an Atari 8-bit or Commodore-64, VIC-20, Coleco >Adam, TI99/4A, PCjr, Spectrum, Sinclair QL, Amstrad or whatever could drive >it. All a computer needs is some output bits, the ability to check for >veritcal blanking and do a page-flip operation on the screen. >High resolution graphics helps, but is not strictly necessary. While this is a possibility, the ST is, in fact, a good choice because the monitors it uses are very high quality good resolution monitors (more important than Bryce seems to think) and because the ST has enough spare ram and cpu power to produce stereo-optic pictures in a reasonable amount of time. You could write the software to just create the images on the machines mentioned, but after you take enough ram for two (or more) full high rez screen images, you may not have enough to make a program that would be useable for more than showing slide-show style pictures... Yes, you could use any of the machines mentioned, BUT, there would probably be major problems using any of them unless you used a very good monitor. Since many of them use a long persistance monitor or tv screens, there could be serious problems trying to get the two images to seperate. --- John Stanley (john@viper.UUCP) Software Consultant - DynaSoft Systems UUCP: ...{amdahl,ihnp4,rutgers}!{meccts,dayton}!viper!john